Drying apparatus.



N0. 688,!52. Patented D60. 3, I90].

' L. ATWUOD.

DRYING APPARATUS.

(Application filed Apr. 2. 1900.)

2 Sheets-Sheet I.

(No Model.)

ma Monms PETERS cov Pumouwa. wnsnmsrou. n. c.

No. 688,!52. Patented Dec. 3; l90l.

L. ATWUUD. DRYING APPARATUS.

(Application fild Apr. 2, 1900 (No Model.) 2 SheetsSheet 2.

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FFICE.

PATENT LEONARD ATVVOOD, OF PHILADELPHIA, PENNSYLVANIA.

DRYING APPARATUS.

SPECIFICATION formingpart of Letters Patent N 0. 688,152, dated December3, 1901.

Application filed April 2, 1900.

T0 alt whom it may concern:

Be it known that I, LEONARD ATWOOD, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovementsin Drying Apparatus, of which the following is aspecification.

My invention relates to that class of drying apparatus in which thedrying is efiected in a chamber wherein a partial vacuum is maintained,the main object of my invention being to so construct such apparatusthat the partial vacuum can be produced and maintained more readily thanusual and the apparatus operated with less delay and inconvenience.

My invention in its broader embodiments applies generally to apparatusof the class mentioned; but in the accompanying drawings I have shownthe invention as embodied in apparatus for drying brewers grains,several special features of my invention being present in apparatus ofthis character.

In the drawings, Figure l is a longitudinal sectional view of theapparatus. Fig. 2 is an enlarged section of part of the same. Fig. 3 isa transverse section on the line a a, Fig. 2. Fig. 4 is an enlargedtransverse section on the line b b, Fig. 1; and Fig. 5 is an enlargedsectional view of one of the feed or discharge elements of the machine.

The drying of brewers grains in such a manner as to retain in the driedgrains a large percentage of the gluten and other valuable foodconstitutents has proven to be extremely difiicult in practice, anyattempt to express the Water from the mass of grains-by pressure as apreliminary step in the drying operation causing a large percentage ofsuch constituents to escape with theexpressed water. I find, however,that by allowing the Water to drain from the grains or by subjectingthem to but a moderate degree of compression, while at the same timethey are being gradually dried by heat, I am enabled to effect thethorough drying of the grains and at the same time retain therein a veryhigh percentage of the gluten and other valuable food constituentsheretofore lost. The apparatus shown in the drawings and intended forthe accomplishment of this purpose consists of a doublewalled casing 1,the chamber 2 between the walls being a water-chamber and being suppliedwith cold water through a pipe 3, hav- Serial No. 11,200. (No model.)

ing branches 4, the Water being withdrawn from the chamber 2 throughpipes 5, or the flow may, if desired, be the reverse of this, the pipes5 being inlet-pipes and the pipe 3 an outlet. The chamber 6 within thecasing is the vacuum-chamber, partial vacuum being maintained therein byconnecting said chamber through pipes 7 with an ejector air-pump orother form of exhausting apparatus 25, the feeding of the grains intothe chamber 6 and their discharge therefrom being effected by means ofdevices which at the same time con stitute traps for preventing theinflow of air at either the inlet or outlet. Each trapfeeder ortrap-discharger consists, preferably, of a pocketed drum 8, turningloosely in a casing 9, upon which is supported, by means of an elasticplate 21, a segmental shoe 22, which fits snugly to the drum 8 and hasin it an opening through which the grains can pass, said opening formingthe dischargeneck of a hopper 10, which is mounted upon the casing 9. Bythis means a snug fit of the drum and shoe is always maintainedirrespective of the expansion and contraction of the casing 9, the shoe,owing to the plate 21, always having a yielding or elastic bearing uponthe drum. The pocket in the drum 8 and the wings of the shoe 22 are soformed that the mouth of the pocket will be cut off from com municationwith the hopper before said pocket begins to communicate with thechamber 6, and vice versa. Hence the pocket may be filled with grains,and as the drum is turned the pocket will dump its lead of grainswithout offering any opportunity for the inflow of air.

The feeder-drum 8 discharges into a chute 11,at the bottom of which area pair of toothed feed-rolls 12, rotated at such speed that they willdischarge uniformly from the chute the masses of grains intermittentlydumped into the same. From the chute the grains fall onto an endlessbelt or apron 13,0f wire-gauze, perforated plate, or other material,which will permit of the draining away of the water in the mass, thiswater being received in a pan 14.,from which it is withdrawn through adrain-pipe 15. Immediately beneath that portion of thejendless apron 13onto which the grains fall from the chute 11 is a transverse grating 16,extending from side to side of the pan 14 and serving to support theapron against the weight of the grains, which is considerable,as saidgrains are sodden with water. The sides of the pan 14 extend above theendless apron 13, so as to prevent the lateral escape of water from thelatter except into the pan, and a pivoted flap 17, hung to the sides ofthe pan, bears upon the apron at the outer end of the pan in order toprevent the escape of water in that direction. The apron 13 passesaround a series of hollow steam-heated drying-drums 18, contained in thechamber 6, and around these drums also passes another endless apron 19,of felt or other permeable material, these aprons travcling in thedirections indicated by the arrows, so that the mass of grains depositedupon the apron 13 is carried around the cylinders 18 in succession andduring such passage is confined. between the aprons l3 and 19. The drumsare by preference geared together by spur-wheels 27, Fig. 4, so that theentire series may be driven at the same surface speed by power appliedto one of them, and the pipes 28 for the supply of steam to the drumsand for the discharge of the water of condensation therefrom passthrough stuffing-boxes 29 onthe sides of the casing, as shown in Fig.4.. The length of the aprons 13 and 19 is such that the mass of grainsconfined between them is subjected to but little pressure, the waterbeing permitted'to drain naturally therefrom or being caused to escapein the form of vapor due to the heat of the drums. The pan 14 preferablyextends beneath the first few drums of the series in order to receivethe water from the grains during that part of their travel in which saidwater drains freely therefrom. As the grains gradually become freed frommoisture the apron 19 dries and shrinks, thereby reducing its length andcausing it to approach more closely to the reticulated apron 13. Henceas there is a shrinkage in the volume of the mass of grains, due to thedrying of the same, there is a corresponding contraction in the spacebetween the two aprons, so that the grains are properly confined andheld close to the drying-drums until in afully-dried condition.

they reach the point of discharge. Both aprons may be of the characterof the apron 19, if desired, although it is preferable to employ for oneof the aprons a reticulated metal fabric, because of its greaterpermeability. Suitable rollers 20 provide for the proper guidance andsupport of the return-runs of the aprons 13 and 19.

Extending throughout the length of the chamber 6 above the series ofheated dryingdrums 18 is a deflector-plate 23, which is somewhat less inwidth than the said chamber- 6, so that vapor can rise or water ofcondensation can descend between the edges of said deflector-plate andthe side Walls of the chamber. Hence the water due to condensation ofvapor by contact with the water-jacket at the top of the chamber 6 isprevented from csaie falling back upon the drying-cylinders and apronsand is directed to the opposite sides of the chamber.

One of the main features of my invention is the water-jacket providedfor the dryingchamber, and this, as before indicated, may be used inconnection with many forms of drying apparatus in which the dryingoperation is efiected by the application of heat in a chamber wherein apartial vacuum is maintained.

Among the advantages arising from the use of the water-jacket may bementioned the readiness with which the partial vacuum within thedrying-chamber may be produced and maintained. To produce the vacuum,the

air may first be driven from the chamber (5 by an inflow of live steamthrough a suitable valved pipe 26, and the air-outlet and steaminletbeing then closed the steam Within the chamber will be rapidly condensedby contact with the cool jacket and the desired degree of vacuum therebyquickly attained, the exhausting device being then set in operation inorder to maintain it. The duty of the exhausting device in thusmaintaining the vacuum is materially lessened by the fact that the Vaporarising from the drying material is condensed by contact with thejacketed Walls of the dryingchamber, and impairment of the vacuum byleakage of air into the chamber 6 is also prevented by the water-jacketfor the following reason. Deformation of the casing of the apparatus tosome extent naturally follows from the external pressure thereupon whena partial vacuum is produced in the chamber 6, and this leads to astraining and loosening of the joints, which while sufiicient to permita flow of air through them will not permit a like How of water. Hencethe latter acts in the nature of a sealto prevent such inflow of air.Further than this, the waterjacket keeps the casing of the apparatus socool that the attendants can work close to the same withoutinconvenience, the apparatus causing no material risein the temperatureof the room or apartmentin which it is placed, and the jacket alsoprovides a means for readily cooling the chamber 6 when for any reasonit is desired to enter the same.

The ejector-pipe may be provided with a check-valve 30, opening outward,and the drain-pipes 7 and 15 may be long enough to carry water-columnsof a height commensurate with the degree of vacuum maintained, and eachof these pipes may also be provided at the foot of the column withsimilar checkvalves, whereby when a partial vacuum is once produced inthe chamber 6 it may be re tained indefinitely. As results of thisconstruction time is saved in starting the appa ratus after a temporarystoppage and collapse of any of the drying-cylinders is prevented in theevent of the formation of a partial vacuum therein by condensation ofthe steam used for heating the same. In some cases the valvedwater-column drain -pipe may be the only means relied upon to maintainthe vacuum in the chamber 6, water escaping through the valve at thebottom of the column as water of condensation is added at the top,librium.

The various advantages noted must, it will be evident, lessen theexpense and inconvenience of operating the apparatus and otherwise tendto increase the commercial practicability of the same.

Having thus described my invention, I claim and desire to secure byLetters Patent-- 1 1. The combination in adrying apparatus, of ajacketed casing inclosing a drying-chamber, means for supplying water tosaid jacket, means for heating the chamber, and means for producing apartial vacuum therein, substantially as described.

2. The combination in a drying apparatus, of a jacketed casing,inclosing a drying-chamber, means for supplying cold water to saidjacket, heating means within the chamber, means forproducinga partialvacuum therein, and means for conveying material to be dried through thechamber, substantially as described.

3. The combination in a drying apparatus, of a jacketed casing inclosinga drying-chamber, means for supplying cold water to said jacket, aseries of drums within the chamber, means for rotating said drums, meansfor supplying heat thereto, and means for producing apartial vacuum inthe chamber, substantially as described.

4. The combination in a drying apparatus, of a water-jacketed casinginclosing a dryingchamber, heated drums in said chamber, a pair ofcarrying-aprons passing around said drums wholly within the chamber, andinlet and discharge mechanism for the material, substantially asdescribed.

5. The combination in a drying apparatus,

of a double casing inclosing the drying-chamber and forming a jacket atthe top and bot tom and on each side of the chamber, means so as tomaintain the column in equi for supplying cold water to the jacket,means for supplying heat to the chamber, and means for conveyingmaterial therethrough,substantially as described.

6. The combination in afeeding device, of a pocketed drum, a casing freefrom contact therewith,and a shoe bearing upon said drum, and having anelastic support on the casing and an opening for the passage of thematerial, substantially as specified.

7. Drying apparatus comprising a waterjacketed casing containing thedrying-chamber, heated drums within said chamber, a pair of permeableaprons passingaround said drums, means for producing and maintaining apartial vacuum within the drying-chamber, provision for receiving thematerial to be dried between the aprons and for delivering it therefrom,and trap feed and discharge devices for the material, substantially asspeci- 8. Drying apparatus comprising a series of heated drying-drums, apair of aprons passing around said drums, and a feeding device for thematerial to be dried, said feeding device comprising means fordelivering masses of material intermittently, and supplementary meansfor continuously delivering in smaller quantity the masses thusintermittently fed, substantially as specified.

9. Drying apparatus comprising a series of heated dryin g-dru ms, a pairor aprons passing around said drums, one of said aprons beingperforated, means for delivering the material to be dried onto saidperforated apron, a drippan extending beneath said apron and hav-' ingsides projecting above the same, and a pivoted flap bearing upon theapron and extending from side to side of the pan, substantially asspecified.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

LEONARD ATWOOD.

Witnesses:

F. E. BEOHTOLD, J 0s. H. KLEIN.

